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Limited Stress Surface Model for Bending and Torsion Fatigue Loading with the Mean Load Value
Roland Pawliczek1, Dariusz Rozumek1
1Department of Mechanics and Machine Design, Faculty of Mechanical Engineering, Opole University of Technology, 45-271 Opole, Poland.
Materials (Basel, Switzerland)
|November 27, 2021
Summary
This study introduces a new surface model for predicting material stress limits under fatigue loading. The model accurately estimates allowable stress amplitudes for alloy steels, with errors under 18%.
Area of Science:
- Materials Science
- Mechanical Engineering
- Fatigue Analysis
Background:
- Understanding material behavior under cyclic loading is crucial for structural integrity.
- Existing models may not fully capture the influence of mean stress and cycle asymmetry on fatigue life.
- Alloy steels like S355J0 and S355J2G1W are widely used, necessitating accurate fatigue prediction methods.
Purpose of the Study:
- To develop and validate a novel three-parameter surface model for limited stresses.
- To incorporate material sensitivity to cycle asymmetry and its dependence on fatigue cycles.
- To assess the model's predictive accuracy for alloy steels under cyclic bending and torsion with mean loads.
Main Methods:
- Utilized a linear model for stress amplitude transformation considering mean stress.
- Incorporated a coefficient for material sensitivity to cycle asymmetry, dependent on loading cycles.
- Verified the proposed three-parameter surface model against experimental fatigue test data.
Main Results:
- The proposed surface model effectively predicts allowable stress amplitudes for S355J0 and S355J2G1W alloy steels.
- Experimental validation showed prediction errors not exceeding 18%.
- The regions of highest error were found to be relatively small.
Conclusions:
- The developed three-parameter surface model offers a reliable approach for predicting fatigue stress limits in alloy steels.
- The model's accuracy is suitable for engineering applications involving cyclic loading and mean stresses.
- Further research could explore model applicability to a wider range of materials and loading conditions.
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